Fort Gaines, whose batteries unsuccessfully attempted to defeat Union Admiral David Farragut’s forces in Mobile Bay during the US Civil War, is severely endangered by erosion of the Dauphin Island shoreline.

Sometimes the threat to such places is direct and acute, as in the Coltrane home situation. Other times, the site may be stable but threatened by encroaching development.

For instance, a few years ago, the National Trust helped blunt the giant Walt Disney entertainment corporation's plan to create a theme park near Virginia's Civil War battlefields.

The trust says wind-farm and oil exploration threatens Bear Butte, one of this year’s sites. The low mountain in the Black Hills of South Dakota is a place of prayer and meditation for as many as 17 American Indian tribes.

Once the world’s largest and most advanced milling facility, the Pillsbury 'A' Mill in Minneapolis, Minnesota, stands vacant and in need of rehabilitation.

The proposed development, in the trust’s words, “will negatively impact the sacred site and further degrade the cultural landscape.”

According to the trust’s calculations, financial contributions from its members and others have helped save just over half of the threatened sites from destruction since the endangered list started in 1988.